Deprecate parser.ParseDir

The parser.ParseDir function is a helper that walks a directory and turns every Go file it finds into an abstract syntax tree (AST). The Go team has marked this helper as *deprecated*. That means it still works, but the type it returns, ast.Package, is also deprecated. When you use parser.ParseDir in a new project, your IDE will warn you that the function is old and that you should look for a newer alternative.

The warning does not break your code; it just tells you that the library may remove the function in a future release. The change is part of the normal evolution of the standard library, where older APIs are phased out gradually.

If you are writing a small script or a learning example, you can keep using parser.ParseDir. Just be aware that in the future you might need to switch to a different approach, such as walking the directory yourself and calling parser.ParseFile on each file.